v2.4.0.6
Stock-Based Compensation Plans (Details Textual) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Sep. 30, 2012
Stock-Based Compensation Plans (Textual) [Abstract]  
Amount of cash received from the exercise of stock options $ 22
Aggregate intrinsic value of outstanding stock options 5
Aggregate intrinsic value of exercisable stock options 4
Total intrinsic value of options exercised 2
Stock Options [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award  
Weighted average period 2 years 1 month 6 days
Unamortized compensation expense 14
Restricted Stock [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award  
Weighted average period 2 years
Unamortized compensation expense $ 23